I am using a dependency called vision-camera-code-scanner
for QR code scanning in my React Native app. I am getting QR code scan data properly. But i need to pass that data to make an API call. But when i try to do that, it crashes the application. Not sure what should i do here.
Here's my component:
import React, { useState, useCallback, useEffect, useMemo } from "react";
import { StyleSheet, Text } from "react-native";
import {
Camera,
useCameraDevices,
useFrameProcessor,
} from "react-native-vision-camera";
import { useDispatch, useSelector } from "react-redux";
import * as appActions from "../../../redux/app/app.actions";
import { BarcodeFormat, scanBarcodes } from "vision-camera-code-scanner";
interface ScanScreenProps {}
const Scan: React.FC<ScanScreenProps> = () => {
const [hasPermission, setHasPermission] = useState(false);
const devices = useCameraDevices();
const device = devices.back;
const dispatch = useDispatch();
const validateQRStatus = useSelector(validationQRSelector);
const frameProcessor = useFrameProcessor((frame) => {
"worklet";
const detectedBarcodes = scanBarcodes(frame, [BarcodeFormat.QR_CODE], {
checkInverted: true,
});
if (detectedBarcodes?.length !== 0) {
const resultObj = JSON.parse(detectedBarcodes[0].rawValue);
const paramData = `token:${Object.values(resultObj)[0]}`;
validate(paramData);
}, []);
const validate = useCallback((param: string) => dispatch(appActions.validateQR(param)));
useEffect(() => {
(async () => {
const status = await Camera.requestCameraPermission();
setHasPermission(status === "authorized");
})();
}, []);
return (
device != null &&
hasPermission && (
<>
<Camera
style={StyleSheet.absoluteFill}
device={device}
isActive={true}
frameProcessor={frameProcessor}
frameProcessorFps={5}
/>
{/* {barcodes.map((barcode, idx) => (
<Text key={idx} style={styles.barcodeTextURL}>
{barcode.barcodeFormat ": " barcode.barcodeText}
</Text>
))} */}
<Text style={styles.barcodeTextURL}>camera</Text>
</>
)
);
};
export default Scan;
const styles = StyleSheet.create({
barcodeTextURL: {
fontSize: 20,
color: "white",
fontWeight: "bold",
alignSelf: "center",
},
});
CodePudding user response:
Your problem is that a worklet is run in a separate JS thread. If you need to call any function from your main thread you need to use runOnJS
(https://docs.swmansion.com/react-native-reanimated/docs/next/api/miscellaneous/runOnJS/)
import { runOnJS } from 'react-native-reanimated';
const frameProcessor = useFrameProcessor((frame) => {
"worklet";
const detectedBarcodes = scanBarcodes(frame, [BarcodeFormat.QR_CODE], {
checkInverted: true,
});
if (detectedBarcodes?.length !== 0) {
const resultObj = JSON.parse(detectedBarcodes[0].rawValue);
const paramData = `token:${Object.values(resultObj)[0]}`;
runOnJS(validate)(paramData);
}, []);